Concurrency in JavaScript (Node.js)

Modern web applications require high performance and responsiveness. The book "Concurrency in JavaScript (Node.js)" is a comprehensive guide that will help you master all aspects of parallel and asynchronous programming on the Node.js platform. You will learn how to effectively use JavaScript's single-threaded model without blocking the event loop, and how to scale applications using multithreading.

The book is intended for developers already familiar with the basics of JavaScript and Node.js who want to deepen their knowledge of concurrency. It will be useful both for backend engineers building high-load APIs and for microservices developers striving for maximum performance. The reader will learn to avoid common pitfalls of asynchronous code, such as Callback Hell, and master modern patterns for working with threads.

Inside you will find detailed examples and practical scenarios:

• Concurrency Basics: breakdown of the Event Loop, Task Queue, and Microtask Queue.
• Modern async/await: deep dive into promises, generators, and async/await syntax for writing clean and readable code.
• Clustering and Scaling: using the cluster module to distribute load across CPU cores.
• Worker Threads: creating true multithreaded applications for CPU-intensive tasks (encryption, image processing, parsing).
• Thread Management: synchronization, data sharing, message passing between threads, and preventing race conditions.
• Advanced Techniques: working with queues (Bull, RabbitMQ), Producer-Consumer patterns, Throttling, and Debouncing.
• Testing and Debugging: writing tests for asynchronous code, performance profiling, and finding memory leaks.

Special attention is paid to practical examples: from writing a parallel HTTP server to creating a high-performance real-time data processor. Each chapter is accompanied by code that can be immediately applied in your projects.

After reading the book, you will be able to design fault-tolerant systems, efficiently use server resources, and write code that performs well even under high load. This is a must-have for anyone who wants to become an expert in Node.js and take their applications to a new level of performance.